Hi Falko,
thanks for your reply. I don't actually make it far enough in the tutorial to remove nfs-common from dom0. The first time I try to boot into dom0 (at the bottom of p3 of the tutorial) I get the errors.
Any other thoughts?
Cheers,
Finn.

Now reboot the system:
shutdown -r now
At the boot prompt, Grub should now list Xen 3.0 / XenLinux 2.6.12 as the first kernel and boot it automatically. If your system comes up without problems, then everything is fine!

But the system doesn't come up ok. During the boot up into dom0 it has the NFS error.

I tried removing nfs-common in the root install, but it wasn't installed.

Just had a thought: I'm running on an Opteron so should I be using the unofificial sarge-amd64 version of Debian on my basic install? Would this effect the Xen compile from source? It is currently on the i386 3.1r2 but I have found an article here which does it in a different way, but mentions using the right kernel for Opteron machines.

As I said I have used the tutorial to install Xen on other PCs with no problems, so it seems to be a problem specific to this machine. (Sunfire X2100, Opteron singe core, 80GB SATA, 2GB RAM)

I read on the Xen Users list that it tries in desperation to boot from NFS if the proper root fails, hence I wondered if it was an issue with the 64 vs 32 bit processor. I'm pretty sure the grub is pointing it to the right place.